1. Field of the Invention
The invention relates to an x-ray apparatus comprising an apparatus base, a tiltable part, a displaceable carriage for x-ray parts running on the tiltable part along guide rails and having a spring weight compensation or a spring counterbalance having compensation forces which are adjustably motor-driven depending on the apparatus position.
2. Description of the Prior Art
German Pat. No. 968 324 discloses an x-ray apparatus including a spring weight compensation apparatus wherein the weight acting at a load lever is compensated by the counter-force of a single spring attacking at the load lever. The point of attack of the spring is displaced via a crank mechanism for setting the different opposing force required dependent upon the oblique position of the apparatus. Since the range of adjustment of the crank is relatively small but the parts to be moved and their weights are rather great, the compensation cannot be accomplished with the required reliability. Further, a cam is required for achieving a roughly constant spring power given differing positioning of the weight-compensated carriage with a target means or a spotfilm device. A precisely constant spring power, however, is thereby not obtainable. Further, such cams are very difficult to manufacture.
German AS No. 1 047 988 has proposed the displacement of the attack point of the spring weight compensation by means of a spindle driven by a regulating motor, so that a compensation can ensue in accord with the oblique position of the apparatus. A matching of the opposing force to the weight to be compensated is likewise achieved here by cam elements for required longitudinal movements in the direction of the spring compensation.